Selective epitaxial growth is the critical unit process for the formation of semiconductor structures including raised source/drain (RSD) regions used to enable silicon integrated circuit technology, such as complementary metal oxide semiconductor (CMOS) structures on a bulk Si-containing semiconductor or a silicon-on-insulator (SOI) and bipolar devices. As with all selective epitaxial processes, the growth of the RSD is highly dependent on the nature of the surface from which it is grown and, in turn, the pre-epitaxy preparation of that surface. For example, in some bulk silicon and in some partially depleted SOI (PDSOI) and fully depleted SOI (FDSOI) CMOS integration schemes, it is highly desirable to implant the halo and extension implants prior to the growth of the RSD. This leads to dissimilar surfaces in the n-field effect transistor (n-FET) and p-field effect transistor (p-FET) regions. In particular, the p-FET and the n-FET regions have different surface characteristics, in terms of their response to various surface treatments and rate of subsequent epitaxial growth. That is, in these two regions the surface preparation and epitaxial growth are generally dependent on the dopant type in those regions.
In order to simultaneously grow selective epitaxial films in both n-FET and p-FET regions, a surface preparation technique, which comprises techniques such as wet etching, plasma treatment, thermal processing, vapor treatment and other surface modifications, is needed that effectively removes undesired surface films from the desired growth regions.
As the surface characteristics are rendered dissimilar by nature of the implants (including, but not limited to: halo implant and/or source/drain extension implant), one of two results is often afforded: either a less aggressive surface preparation is imparted that does not effectively remove undesired films from one region leading to inadequate simultaneous growth in one region; or, a more aggressive surface preparation is used which allows simultaneous growth, but results in excessive thinning of the underlying crystalline or polycrystalline surface from which the epitaxial film is grown.
In view of the drawbacks mentioned with prior art processing of RSD regions, there is a need for providing a method which allows for simultaneous, uniform selective or non-selective epitaxial. growth of a material from surfaces, e.g., regions, having similar or dissimilar surface characteristics, without imparting substrate thinning.